Cline releases open-source agent runtime SDK for coding agents

@cline/sdk has been released as the open-source agent runtime that powers the entire Cline product lineup. Discarding the previous IDE-dependent structure, the core agent loop has been rebuilt as a standalone SDK, and Cline has already moved its own CLI and Kanban onto it, with the VS Code and JetBrains extensions following.

The architecture centers on separating responsibilities by layer.

• @cline/shared: basic types and utilities
• @cline/llms: a provider layer covering Anthropic, OpenAI, Google, AWS Bedrock, Mistral, LiteLLM, and OpenAI-compatible endpoints
• @cline/agents: a stateless agentic loop handling iteration, tool orchestration, and event emission
• @cline/core: stateful orchestration responsible for session lifecycle, persistence, and config discovery

Thanks to this separation, switching providers is a matter of configuration change rather than code modification. The full stack can be installed with npm install @cline/sdk, and individual packages can also be pulled in separately as needed.

The effects of the rebuild are clear. Sessions no longer die on UI restart and can now move between surfaces, and the changes came together with prompt rewrites, improved context management, and adjustments to how tools are exposed. As a result, on claude-opus-4.7, it scored 74.2% on Terminal Bench 2.0, surpassing Claude Code's 69.4%, and on the open-weight model kimi-k2.6, it scored 55.1%, higher than OpenCode's 37.1%.

Agent teams and subagents come built into the SDK by default. Sessions can hand off work to specialist agents and share progress and handoff notes, while plugins handle tool registration, observing lifecycle events, adding rules, and even adjusting what information the model sees. CRON jobs, checkpointing, web search, and MCP connectors are also included natively, and the experimental connector channel via cline connect directly links agents to Telegram, WhatsApp, Slack, and more.

Cline describes itself as an early-stage agentic coding experience, stating that it currently serves more than 7 million developers. Following Cline CLI 2.0 and Cline Kanban, this SDK marks an infrastructure shift that puts the entire Cline product lineup onto a shared, open foundation.